Anti-friction metal



' "U ITED STATES P N F VVILLIAM M. BUBNHAM, OF CHICAGO, ILLINOIS.

ANTIEFRICTION METALA SPECIFICATION forming part of Letters Patent No. 308,874, dated December 9, 1884.

Application filed January 31,1884. (Specimens) T all whom, it may concern:

Be it known that I, WILLIAM M. BURN- HAM, residingat Chicago, in the county of Cook and State of Illinois, and acitizen of the United States, have invented a new and useful Improvement in Anti-Friction Metal, of

which the following is a full description.

It has been the common practice in the manufacture of anti-friction metals for jour-' nal-bearings and other analogous uses to, com; bine plumbago with various metals in" various proportions and by numerousme'thods; but in every instance as now practiced the plumbago has been mixed with the various metals in such manner as to destroy the tenacity and toughness of the metal, thereby greatly reducing the wearing property of the composition, and consequently the value of the antifriction metal for the purpose for which it is used.-

The object of this invention is to confine the plumbago in metals so as to have its particles heldin their natural state without being mixed and permanently united with the metals, leaving the plumbago free to separate and be set free as the metals by which itis confined wear away, and thereby prevent, to

a large extent, the heating of the journal and;

its [0021, and decreasing the rapid wearing from this cause; and this object I accomplish as hereinafter described,

The following metals, in the proportions named, will be found well adapted for wrapping up and holding'the plumbago in its 5 so long as the variation does not prevent the plumbago from being held in its natural and free state by the metals with which it is enveloped. The metals for the mixture are melted together, and when melted should be about the consistency of ordinary plasterers mortar, so as to be readily handled with a trowel, iron which it can be turned or brought into any desired shape, in much the same manner as soft putty or mortar can be handled, and when in this state it is to be poured and wrapped over the plumbago without stirring or agitating, by which 'means the plumbago is enveloped by the metal, so that the particlesare held in a natural state, being only confined of the plumbago temporarily by the metal leaves it free, so-as to separate from the metal part of the composition as the same wears away in use, allowing the plumbago to escape in its natural state and come between the journal and the lining of the box and act 'to prevent any overheating of the parts. By thus enveloping or confining the plumbago temporarily with the metals the natural toughness of the metals is not interfered with, and at the same time the grinding or rubbing of powder by use is overcome, and the use of a lubricant is dispensed with, as the plumbago acts and keeps the parts soft and pliable and will be wrapped up, but held in cells formed around its particles.

What I claim as new, and desire to secure by, Letters Patent, is-

An anti-friction metal consisting of plum envelope or cell without incorporation with metals, substantially as described.

WILLIAM M. BURNHAM.

Witnesses:

O. W. Bonn, ALBERT: H. \ADAMS.

temporarily in the metal. This envelopingbago held in its natural state in a metallic paddle,or anyother suitable instrument'by the anti-friction metal, as a whole, into fine 1 in a clean, polished condition. The plumbago 

